The Emergency Department (ED) allows patients to access a nonstop urgent medical services in the health service. A poor service delivery can often have a negative impact on the entire health service. It may put patient’s life in risk and increase patient waiting time. It also increases pressure on ED seeking external resources which will consequently in- crease cost and cause staff sickness due to workload pressure. Moreover, it increases pressure on other health services such as Ambulance services and social care. A poor service delivery is often the outcome of a reactive strategy to a chaining demand in the ED planning system. An accurate forecast of ED attendance can be used as a planning aid towards a proactive strategy to improve the quality of service. This has now became a priority in the EDs of the National Health Service (NHS), UK. Among factors that may impact the ED attendance, special events such as public holidays and festive days play an important role. In this paper, we propose a forecasting model that outperforms benchmarks by incorporating the effect of special events.